Latest NYC DCAS Electrician 2026/2027 Exam verified with correct answers plus
rationales /instant pdf
1. What is the primary purpose of a circuit breaker?
A. Increase voltage
B. Protect a circuit from excessive current
C. Increase resistance
D. Store electrical energy
Answer: B. Protect a circuit from excessive current
Rationale: A circuit breaker opens the circuit when current exceeds its designed limit, helping
protect conductors and equipment.
2. Which unit measures electrical current?
A. Volt
B. Ohm
C. Ampere
D. Watt
Answer: C. Ampere
Rationale: Current is measured in amperes (amps).
3. Which unit measures electrical resistance?
A. Ohm
B. Volt
C. Ampere
D. Watt
Answer: A. Ohm
Rationale: Resistance is measured in ohms (Ω).
4. Which unit measures electrical potential difference?
,A. Ampere
B. Volt
C. Ohm
D. Watt
Answer: B. Volt
Rationale: Voltage represents electrical potential difference and is measured in volts.
5. Which formula represents Ohm's Law?
A. V = IR
B. P = I/R
C. R = VI
D. I = VR
Answer: A. V = IR
Rationale: Ohm's Law states that voltage equals current multiplied by resistance.
6. A 120-volt circuit has a resistance of 20 ohms. What current flows through the
circuit?
A. 2 A
B. 4 A
C. 6 A
D. 10 A
Answer: C. 6 A
Rationale: I = V/R = 120/20 = 6 amperes.
7. Which formula is used to calculate electrical power?
A. P = VI
B. P = V/R
C. P = I/R
D. P = R/V
Answer: A. P = VI
,Rationale: Electrical power in watts equals voltage multiplied by current.
8. A 120-V load draws 5 A. What is its power consumption?
A. 24 W
B. 125 W
C. 600 W
D. 1,200 W
Answer: C. 600 W
Rationale: P = VI = 120 × 5 = 600 watts.
9. In a series circuit, the current:
A. Is the same through each component
B. Is always zero
C. Is different through every component
D. Exists only across the first component
Answer: A. Is the same through each component
Rationale: A series circuit provides a single path for current.
10. In a parallel circuit, each branch generally has:
A. The same voltage
B. No voltage
C. A different source voltage
D. Zero resistance
Answer: A. The same voltage
Rationale: Parallel branches are connected across the same two points, so the voltage across
each branch is the same.
11. What is the primary purpose of grounding an electrical system?
, A. Increase load current
B. Provide a path for fault current and reduce shock hazards
C. Increase resistance
D. Increase normal operating voltage
Answer: B. Provide a path for fault current and reduce shock hazards
Rationale: Grounding and bonding help provide an effective fault-current path so protective
devices can operate.
12. Which conductor normally carries current back from a load to the source in
a typical single-phase circuit?
A. Equipment grounding conductor
B. Neutral conductor
C. Bonding jumper only
D. Ground rod
Answer: B. Neutral conductor
Rationale: In a typical grounded circuit, the neutral is the grounded circuit conductor that
carries return current under normal operation.
13. What is the purpose of bonding?
A. Establish electrical continuity between conductive parts
B. Increase circuit resistance
C. Eliminate all current
D. Reduce conductor size
Answer: A. Establish electrical continuity between conductive parts
Rationale: Bonding connects conductive components so they remain at substantially the same
electrical potential and provides an effective fault-current path.
14. Which device is designed to provide personnel protection from certain
ground-fault conditions?
A. GFCI
B. Transformer
rationales /instant pdf
1. What is the primary purpose of a circuit breaker?
A. Increase voltage
B. Protect a circuit from excessive current
C. Increase resistance
D. Store electrical energy
Answer: B. Protect a circuit from excessive current
Rationale: A circuit breaker opens the circuit when current exceeds its designed limit, helping
protect conductors and equipment.
2. Which unit measures electrical current?
A. Volt
B. Ohm
C. Ampere
D. Watt
Answer: C. Ampere
Rationale: Current is measured in amperes (amps).
3. Which unit measures electrical resistance?
A. Ohm
B. Volt
C. Ampere
D. Watt
Answer: A. Ohm
Rationale: Resistance is measured in ohms (Ω).
4. Which unit measures electrical potential difference?
,A. Ampere
B. Volt
C. Ohm
D. Watt
Answer: B. Volt
Rationale: Voltage represents electrical potential difference and is measured in volts.
5. Which formula represents Ohm's Law?
A. V = IR
B. P = I/R
C. R = VI
D. I = VR
Answer: A. V = IR
Rationale: Ohm's Law states that voltage equals current multiplied by resistance.
6. A 120-volt circuit has a resistance of 20 ohms. What current flows through the
circuit?
A. 2 A
B. 4 A
C. 6 A
D. 10 A
Answer: C. 6 A
Rationale: I = V/R = 120/20 = 6 amperes.
7. Which formula is used to calculate electrical power?
A. P = VI
B. P = V/R
C. P = I/R
D. P = R/V
Answer: A. P = VI
,Rationale: Electrical power in watts equals voltage multiplied by current.
8. A 120-V load draws 5 A. What is its power consumption?
A. 24 W
B. 125 W
C. 600 W
D. 1,200 W
Answer: C. 600 W
Rationale: P = VI = 120 × 5 = 600 watts.
9. In a series circuit, the current:
A. Is the same through each component
B. Is always zero
C. Is different through every component
D. Exists only across the first component
Answer: A. Is the same through each component
Rationale: A series circuit provides a single path for current.
10. In a parallel circuit, each branch generally has:
A. The same voltage
B. No voltage
C. A different source voltage
D. Zero resistance
Answer: A. The same voltage
Rationale: Parallel branches are connected across the same two points, so the voltage across
each branch is the same.
11. What is the primary purpose of grounding an electrical system?
, A. Increase load current
B. Provide a path for fault current and reduce shock hazards
C. Increase resistance
D. Increase normal operating voltage
Answer: B. Provide a path for fault current and reduce shock hazards
Rationale: Grounding and bonding help provide an effective fault-current path so protective
devices can operate.
12. Which conductor normally carries current back from a load to the source in
a typical single-phase circuit?
A. Equipment grounding conductor
B. Neutral conductor
C. Bonding jumper only
D. Ground rod
Answer: B. Neutral conductor
Rationale: In a typical grounded circuit, the neutral is the grounded circuit conductor that
carries return current under normal operation.
13. What is the purpose of bonding?
A. Establish electrical continuity between conductive parts
B. Increase circuit resistance
C. Eliminate all current
D. Reduce conductor size
Answer: A. Establish electrical continuity between conductive parts
Rationale: Bonding connects conductive components so they remain at substantially the same
electrical potential and provides an effective fault-current path.
14. Which device is designed to provide personnel protection from certain
ground-fault conditions?
A. GFCI
B. Transformer
